Not Applicable
Not Applicable
NOT APPLICABLE
The present invention relates generally to optical instruments, and more specifically to infrared microscopes such as used for Fourier transform infrared spectroscopy (FT-IR).
Infrared microscopes are known, and the technology is well developed. A representative infrared microscope, marketed under the UMA 600 mark, is available from Bio-Rad Laboratories, Inc., Hercules, Calif. (Digilab Division, Randolph, Mass.). The infrared microscope is typically used with an FT-IR spectrometer, also available from Bio-Rad Laboratories. Also, it is well known that the microscope objective is normally removable from the microscope to enable the use of many different types of objective.
The typical infrared microscope setup has a an objective spaced above a sample stage with the objective facing downwardly, and the microscope is operated in transmission mode or reflection mode, depending on the particular properties of the sample that are to be measured. In transmission mode, the infrared light is directed upwardly through a condenser, which focuses the light on the sample. Light passing through the sample and emanating from the sample plane is collected by the objective, and the light travels along an optical train to an infrared detector. In a reflectance measurement, the infrared light is directed downwardly through the objective to encounter the sample from above, and light reflected from the sample is collected by the objective and detected as outlined above.
Infrared microscopy, especially when performed in conjunction with an FT-IR spectrometer, has been used to analyze a vast array of samples. The main constraint on the sample is that it be sufficiently small to fit on the sample stage. When analysis of a large body of material is required, small amounts of material are removed and placed on the sample stage for analysis. This may not be a feasible or desirable treatment for such samples as a valuable painting, a ceramic, or a vehicle tire.
One prior art approach to allow viewing of a sample in a sideways direction has been to design a turret having its axis of rotation at a 45-degree angle to the vertical axis and providing objective mounting threads to allow a given objective to assume a vertical orientation in normal operation or a horizontal orientation for sideways viewing. The microscope incorporates a movable mirror that is moved from one position to the other when the turret is rotated. This works in its intended way for microscopes designed to provide the sideways viewing capability, but the mechanism must be incorporated into every microscope at the time of manufacture, and is not available for pre-existing microscopes that were not built with this capability.
The present invention provides a sideways viewing capability to microscopes, including microscopes that were not originally manufactured with such capability. Therefore, the invention overcomes the requirement, in at least some microscopes, that a sample be small, or that a small portion be removed from a larger sample, thereby allowing large samples to be tested non-destructively. Thus it is possible for a manufacturer to configure the microscope without the sideways viewing capability, and allow users needing such capability to easily retrofit the microscope to add the capability.
In short, the invention contemplates interposing an adapter between the objective and the microscope. The adapter has a support structure to which are mounted an objective-engaging structure, a microscope-engaging structure, and a reflecting element. The objective-engaging structure and the microscope-engaging structure, when mounted to the support structure, are characterized by respective axes that are non-collinear, and the reflecting element is positioned and oriented so that light incident along the objective-engaging structure""s axis is reflected to travel along the microscope-engaging structure""s axis. In specific embodiments, the relative angle between the axes is 90 degrees.
Thus, when the adapter is mounted to the microscope and the objective is mounted to the adapter, the microscope is capable of viewing a sample at an angle displaced from the vertical. In the specific example of a 90-degree angle, a sample of any size can be viewed merely by bringing the sample beside the microscope and in front of the objective.
Accordingly, the invention provides an adapter and a method of retrofitting microscopes to provide a sideways viewing capability.